CN115078888B - High voltage DC interference test method, device and polarization characteristic test device - Google Patents

Abstract

The application provides a method and a device for testing high-voltage direct current interference and a device for testing polarization characteristics, wherein the method comprises the following steps: monitoring the natural corrosion potential of the pipeline sample in real time, and testing the polarization characteristic curve of the pipeline sample by a polarization characteristic testing device after the natural corrosion potential is stable; measuring the layering soil resistivity of an influence area of high-voltage direct current interference on a pipeline sample; establishing a geometric model of the pipeline under high-voltage direct current interference based on the polarization characteristics of the pipeline sample and the layering soil resistivity; calculating a polarization boundary curve of the pipeline sample based on the polarization characteristic curve and the damage rate of an external anti-corrosion coating of the metal material to be tested for preparing the pipeline sample; and determining the influence result of the high-voltage direct current interference on the pipeline based on the geometric model of the pipeline under the high-voltage direct current interference and the polarization boundary condition of the pipeline sample. The method can obtain accurate influence results of high-voltage direct current interference on the pipeline based on the polarization characteristic curve and the layering soil resistivity detected in the real service environment.

Description

High voltage DC interference test method, device and polarization characteristic test device

Technical Field

The present application relates to the technical field of power interference, and in particular to a method and device for testing high-voltage direct current interference and a polarization characteristic testing device.

Background Art

With the increase in my country's demand for energy, domestic high-voltage direct current transmission projects and oil and gas pipelines have developed rapidly. Both high-voltage direct current transmission systems and long-distance oil and gas pipelines are transported through buried pipelines. Therefore, high-voltage direct current transmission systems and long-distance oil and gas pipelines are often built close to each other. When the grounding electrode of the high-voltage direct current transmission system operates in a single-pole mode, thousands of amperes of current will flow into the earth, causing serious interference to nearby buried metal pipelines and increasing the risk of corrosion of buried pipelines.

The amplitude of high-voltage DC interference is high and the impact range is wide. There are problems such as difficulty in adjusting parameters and low efficiency during field tests. It is difficult for laboratories to simulate the working conditions of pipelines with thousands of meters of high-voltage DC interference. At present, researchers usually use numerical simulation calculations to effectively predict high-voltage DC interference and design optimization mitigation solutions. The most commonly used software for high-voltage DC numerical simulation calculations are ANSYS, CDEGS, and BEASY. With the help of numerical simulation calculations, researchers analyzed the interference intensity of high-voltage DC on pipelines under factors such as the damage rate of the anti-corrosion layer, the distance from the pipeline to the grounding electrode, and the soil resistivity.

However, the accuracy of numerical simulation technology is affected by many factors when it is used, among which the determination of the boundary conditions of the pipeline is the most important. Currently, it is difficult for researchers to obtain the accurate boundary conditions of the pipeline in the service environment, which brings difficulties to the numerical simulation analysis of the interference law of high-voltage direct current on the pipeline.

The present application proposes a method and device for testing high-voltage DC interference and a polarization characteristic testing device, which can more accurately obtain the polarization boundary conditions required for numerical simulation calculation of high-voltage DC interference, thus providing a guarantee for the safe operation of the pipeline network.

Summary of the invention

The present application aims to solve at least one of the above-mentioned technical defects. In view of this, the present application provides a test method, device and polarization characteristic test device for high-voltage DC interference, which are used to solve the technical defect in the prior art that it is difficult to obtain accurate boundary conditions of pipelines in a service environment, thereby improving the accuracy of numerical simulation calculations, effectively reflecting the impact of pipeline corrosion under high-voltage DC interference, and providing an important reference for pipeline risk assessment.

A method for testing high voltage DC interference, comprising:

Real-time monitoring of the natural corrosion potential of the pipeline sample, and after the natural corrosion potential is stabilized, testing the polarization characteristic curve of the pipeline sample by a pre-set polarization characteristic testing device;

The Wenner quadrupole method was used to measure the resistivity of the layered soil in the area affected by high voltage DC interference on the pipeline specimen.

Using boundary element numerical simulation method, based on the polarization characteristic curve of the pipeline sample and the resistivity of the layered soil, a geometric model of the pipeline subjected to high voltage direct current interference is established;

Calculating the polarization boundary curve of the pipeline sample based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample;

Based on the geometric model of the pipeline being disturbed by high-voltage direct current and the polarization boundary conditions of the pipeline sample, the influence result of the high-voltage direct current interference on the pipeline is determined.

Preferably, the Wenner quadrupole method is used to measure the resistivity of layered soil in the area affected by the high voltage DC interference on the pipeline, including:

Four test sites are set within a preset distance of the pipeline sample, and the soil resistivity at a preset number of different depths is tested using the Wenner quadrupole method;

The average value of the soil resistivity at the plurality of different depths is calculated and used as the layered soil resistivity of the area affected by the pipeline sample.

Preferably, testing the polarization characteristic curve of the pipeline sample by the polarization characteristic testing device includes:

The polarization characteristic test device gradually moves negatively from the natural corrosion potential to -1500mV _CSE in steps of 0.5-1mV/s, measures the relationship between the polarization potential and the polarization current density of the pipeline sample, and generates a polarization characteristic curve of the pipeline sample.

Preferably, the polarization boundary curve of the pipeline sample is calculated based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample, including:

The polarization potential is kept unchanged, the product of the external anti-corrosion coating breakage rate of the metal material to be tested and the polarization current density of the pipeline sample is used as the new polarization current density, the polarization characteristic curve of the pipeline sample is adjusted, and the polarization boundary curve of the pipeline sample is generated.

A polarization characteristic testing device comprises a working electrode, an auxiliary electrode, a reference electrode, a support tube and an electrochemical workstation;

The working electrode is a pipe sample made of the metal material to be tested;

The electrochemical workstation is used to test the polarization characteristics of the pipeline sample;

The support tube is used to be arranged in the soil at the test site to provide support for the entire polarization characteristic test device.

Preferably, the reference electrode is a copper/saturated copper sulfate reference electrode, a MnO ₂ reference electrode or a zinc reference electrode.

Preferably, the auxiliary electrode is a platinum electrode or a mixed metal oxide (MMO) electrode.

Preferably, the support tube is made of PVC material.

A high voltage DC interference testing device, comprising:

A polarization characteristic determination unit, used for real-time monitoring of the natural corrosion potential of the pipeline sample, and after the natural corrosion potential is stabilized, testing the polarization characteristic curve of the pipeline sample by a pre-set polarization characteristic testing device;

A layer resistivity determination unit for measuring the layer soil resistivity in the area affected by high voltage DC interference on the pipeline specimen using the Wenner quadrupole method;

An interference model establishment unit is used to establish a geometric model of the pipeline being interfered by high voltage direct current based on the polarization characteristic curve of the pipeline sample and the resistivity of the layered soil by using a boundary element numerical simulation method;

A boundary curve determination unit, used to calculate the polarization boundary curve of the pipeline sample based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample;

The impact result determination unit is used to determine the impact result of the high-voltage direct current interference on the pipeline based on the geometric model of the pipeline being interfered by the high-voltage direct current and the polarization boundary conditions of the pipeline sample.

Preferably, the layered resistivity determination unit comprises:

A resistivity determination unit is used to set four test sites within a preset distance of the pipeline sample and test the soil resistivity at a preset number of different depths using a Wenner quadrupole method;

The average calculation unit is used to calculate the average value of the soil resistivity at the plurality of different depth positions and use it as the layered soil resistivity of the area affecting the pipeline sample.

It can be seen from the above technical solutions that the test method, device and polarization characteristic test device for high-voltage DC interference provided in the embodiment of the present application monitor the natural corrosion potential of the pipeline sample in real time. After the natural corrosion potential is stabilized, the polarization characteristic curve of the pipeline sample is tested by a pre-set polarization characteristic test device, and then the layered soil resistivity of the area affected by the high-voltage DC interference on the pipeline sample is measured by the Wenner quadrupole method to establish a geometric model of the pipeline affected by high-voltage DC interference. Based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample, the polarization boundary curve of the pipeline sample is calculated, and finally, based on the geometric model of the pipeline affected by high-voltage DC interference and the polarization boundary conditions of the pipeline sample, the impact result of the high-voltage DC interference on the pipeline is determined.

This application utilizes a polarization characteristic test device consisting of a working electrode, an auxiliary electrode, a reference electrode, a support tube, and an electrochemical workstation to accurately measure the polarization characteristics of the pipeline in a real service environment. At the same time, the Wenner quadrupole method is used to measure the layered soil resistivity of the area affected by high-voltage DC interference in a real service environment. Based on the polarization characteristic curves and layered soil resistivity detected in a real service environment, this application can effectively improve the accuracy of numerical simulation calculations, thereby obtaining more accurate results of the impact of high-voltage DC interference on the pipeline. The impact results can effectively reflect the impact of pipeline corrosion under high-voltage DC interference, provide an important reference for pipeline risk assessment, and improve the reliability of safe pipeline operation.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

FIG1 is a schematic diagram of a polarization characteristic testing device provided in an embodiment of the present application;

FIG2 is a flow chart of a method for testing high voltage DC interference according to an embodiment of the present application;

FIG3 is a schematic diagram of the structure of a high-voltage DC interference testing device disclosed in an embodiment of the present application.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

The test method of high-voltage DC interference first requires the construction data of the high-voltage DC transmission system and the long-distance oil and gas pipeline, and inquires the basic information such as pipeline specifications, coordinates, materials, and external anti-corrosion coating damage rate, and verifies the accuracy of the information on site. Prepare and bury the polarization characteristic test device. After the natural corrosion potential is stabilized, the polarization characteristics of the pipeline sample are obtained through the polarization characteristic test device, and the Wenner quadrupole method is used to measure the layered soil resistivity in the high-voltage DC interference area. Finally, according to the boundary element numerical simulation method, based on the polarization characteristic curve of the pipeline sample and the layered soil resistivity, a geometric model of the pipeline affected by high-voltage DC interference is established, and the polarization boundary curve of the pipeline sample is obtained. Therefore, based on the geometric model of the pipeline affected by high-voltage DC interference and the polarization boundary conditions of the pipeline sample, the impact of high-voltage DC interference on the pipeline can be analyzed.

In conjunction with FIG1 , the following describes a polarization characteristic test device according to an embodiment of the present application, which can accurately measure the polarization characteristics of a pipeline in a real service environment. As shown in FIG1 , the polarization characteristic test device may include: a working electrode, an auxiliary electrode, a reference electrode, a support tube, and an electrochemical workstation;

The working electrode is a pipe sample made of the metal material to be tested;

The electrochemical workstation is used to test the polarization characteristics of the pipeline sample;

The support tube is used to be arranged in the soil at the test site to provide support for the entire polarization characteristic test device.

Optionally, the reference electrode is a copper/saturated copper sulfate reference electrode, a MnO ₂ reference electrode or a zinc reference electrode.

Optionally, the auxiliary electrode is a platinum electrode or a mixed metal oxide (MMO) electrode.

Optionally, the support tube is made of PVC material.

Specifically, a suitable test location is selected on site to bury the polarization characteristic test device, and the polarization characteristic test device is buried in the area of high-voltage DC interference of the target pipeline, and the buried depth of the polarization characteristic test device is the same as the target pipeline. The pipeline sample made of the metal material to be tested is used as the working electrode in the polarization characteristic test device, and can further be a sample made of X80 steel material of the pipeline to be tested. The reference electrode can be a copper/saturated copper sulfate reference electrode, an _MnO2 reference electrode, a zinc reference electrode or other types of reference electrodes. The auxiliary electrode can be a platinum electrode or a mixed metal oxide MMO electrode. The support tube is inserted into the soil at the test site to provide support for the entire polarization characteristic test device, and the support tube can be a sample support tube made of PVC material. Due to the physical and chemical interaction between the metal and the environment, the metal properties may change. The natural corrosion potential refers to the potential measured when the metal reaches a stable corrosion state when there is no external current. After the polarization characteristic test device is buried underground, it is necessary to wait for the working electrode, that is, the natural corrosion potential of the pipeline sample to stabilize, and then test its polarization characteristics through the electrochemical workstation in the polarization characteristic test device to obtain the polarization characteristics of the pipeline sample under the actual service environment.

It can be seen from the above technical solutions that the polarization characteristic testing device provided in the embodiment of the present application can realize accurate measurement of the polarization characteristics of the pipeline in a real service environment, thereby effectively improving the accuracy of numerical simulation calculations, and obtaining relatively accurate results of the impact of high-voltage DC interference on the pipeline. The impact results can effectively reflect the impact of pipeline corrosion under high-voltage DC interference, provide an important reference for pipeline risk assessment, and improve the reliability of safe operation of the pipeline.

FIG2 is a flow chart of a method for testing high-voltage DC interference disclosed in an embodiment of the present application. The method for testing high-voltage DC interference can be applied to a device for testing high-voltage DC interference. As shown in FIG2 , the method may include:

Step S1, real-time monitoring of the natural corrosion potential of the pipeline sample, after the natural corrosion potential is stabilized, testing the polarization characteristic curve of the pipeline sample by a pre-set polarization characteristic testing device.

Specifically, after the polarization characteristic device is installed, the natural corrosion potential of the working electrode, that is, the pipeline sample, is monitored in real time. After the natural corrosion potential is stabilized, the polarization characteristics of the pipeline sample are tested by the electrochemical workstation in the polarization characteristic test device to obtain the polarization characteristic curve of the pipeline sample, which is the polarization characteristic of the pipeline sample in the real service environment. The polarization characteristic curve can characterize the relationship between the polarization potential and the polarization current density of the pipeline sample in the real service environment and in the real environment under the interference of high voltage DC.

Further, testing the polarization characteristic curve of the pipeline sample by the polarization characteristic testing device may include:

The polarization characteristic test device gradually moves negatively from the natural corrosion potential to -1500mV _CSE in steps of 0.5-1mV/s, measures the relationship between the polarization potential and the polarization current density of the pipeline sample, and generates a polarization characteristic curve of the pipeline sample.

Specifically, in the generated polarization characteristic curve, each point represents the polarization current density corresponding to the pipeline sample under the polarization potential. The polarization characteristic curve is a curve formed by each polarization potential and the unique corresponding polarization current density.

Step S2: using the Wenner quadrupole method to measure the resistivity of the layered soil in the area affected by the high voltage DC interference on the pipeline sample.

Specifically, soil resistivity is an important factor in determining the resistance value of the grounding system. Its size directly affects the size of the grounding equipment resistance, whether the ground grid distribution is reasonable, and the contact voltage and step voltage, which are important indicators. In this application, soil resistivity is used to combine the polarization characteristic curve of the pipeline sample to establish a geometric model of the pipeline being interfered with by high-voltage DC. Factors that affect soil resistivity include the amount of ions and water content in different soils. Different soil properties have different resistivities. For example: grounding detection of sandy soil, grounding occasions with more gravel, riverbeds, soil with high water content near lakes, and indoor buildings, etc., and the change in resistivity also varies with the seasons.

The principle of the Wenner quadrupole method for detecting soil resistivity is: the soil resistivity test formula is ρ = 2πaR (ohm·meter). The alternating current flowing between the grounding electrode and the current electrode is I, the potential difference between the voltage electrode and the auxiliary ground electrode is V, V divided by I is the grounding resistance value R, the electrode spacing is a, and the resistivity ρ is obtained according to the above formula. When the distance a of each electrode is the same, it is the Wenner method. For the convenience of calculation, the electrode spacing a should be set to be much larger than the burial depth h, and generally a>20h should be satisfied.

Step S3: using a boundary element numerical simulation method, based on the polarization characteristic curve of the pipeline sample and the resistivity of the layered soil, a geometric model of the pipeline subjected to high voltage direct current interference is established.

Specifically, the boundary element numerical simulation method has the advantages of a small number of units and simple data preparation, and approximates the boundary conditions by using a function that satisfies the control equation. In this application, based on the polarization characteristic curve of the pipeline sample and the layered soil resistivity obtained in step S1 and step S2, the boundary element numerical simulation method is used to establish a geometric model of the pipeline subjected to high voltage direct current interference.

Step S4, calculating the polarization boundary curve of the pipeline sample based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested that makes up the pipeline sample.

Specifically, according to the type of metal material anti-corrosion layer of the pipeline sample, the outer anti-corrosion layer damage rate is determined, that is, the outer anti-corrosion coating damage rate of the metal material to be tested of the pipeline sample is made, and the polarization characteristic curve of the pipeline sample is corrected by using the outer anti-corrosion layer damage rate. Keeping the polarization potential unchanged, the polarization current density is multiplied by the anti-corrosion layer damage rate to obtain a new current density, and the new polarization potential and polarization current density are plotted to obtain the polarization boundary condition of the sample with the anti-corrosion layer.

Further, based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample, calculating the polarization boundary curve of the pipeline sample may include:

The polarization potential is kept unchanged, the product of the external anti-corrosion coating breakage rate of the metal material to be tested and the polarization current density of the pipeline sample is used as the new polarization current density, the polarization characteristic curve of the pipeline sample is adjusted, and the polarization boundary curve of the pipeline sample is generated.

Specifically, the polarization potential in the polarization boundary curve is kept unchanged, and the current density corresponding to each polarization potential is determined as the new current density obtained by multiplying the original polarization current density and the anti-corrosion layer damage rate. The new polarization potential and polarization current density are plotted to obtain the polarization boundary condition of the sample with the anti-corrosion layer. Compared with the polarization characteristic curve before adjustment, the polarization potential of the polarization boundary curve is consistent with the polarization characteristic curve, but the polarization current density corresponding to each polarization potential becomes the product of the original polarization current density and the external anti-corrosion coating damage rate.

Each point in the polarization boundary curve represents a corresponding relationship between a polarization potential and a polarization current density. In actual research, each corresponding relationship between a polarization potential and a polarization current density is a polarization boundary, and the polarization boundary curve is a collection of polarization boundaries composed of the corresponding relationships between polarization potentials and polarization current densities.

Step S5: determining the influence of the high voltage direct current interference on the pipeline based on the geometric model of the pipeline subjected to the high voltage direct current interference and the polarization boundary conditions of the pipeline sample.

Specifically, based on the geometric model of the pipeline affected by high-voltage DC interference and the polarization boundary conditions of the pipeline sample, boundary element or finite element numerical simulation software is used to solve the impact of high-voltage DC interference on the pipeline, and the results can be obtained.

Compared with the existing solutions, this application is based on the accurate measurement of the polarization characteristics of the pipeline in the actual service environment, which can effectively improve the accuracy of numerical simulation calculations and obtain more accurate results on the impact of high-voltage DC interference on the pipeline.

It can be seen from the above technical solutions that the test method for high-voltage DC interference provided in the embodiment of the present application monitors the natural corrosion potential of the pipeline sample in real time. After the natural corrosion potential is stabilized, the polarization characteristic curve of the pipeline sample is tested by a pre-set polarization characteristic test device, and then the layered soil resistivity of the area affected by the high-voltage DC interference on the pipeline sample is measured by the Wenner quadrupole method to establish a geometric model of the pipeline affected by high-voltage DC interference. Based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample, the polarization boundary curve of the pipeline sample is calculated, and finally, based on the geometric model of the pipeline affected by high-voltage DC interference and the polarization boundary conditions of the pipeline sample, the impact result of the high-voltage DC interference on the pipeline is determined.

This application utilizes a polarization characteristic test device consisting of a working electrode, an auxiliary electrode, a reference electrode, a support tube, and an electrochemical workstation to accurately measure the polarization characteristics of the pipeline in a real service environment. At the same time, the Wenner quadrupole method is used to measure the layered soil resistivity of the area affected by high-voltage DC interference in a real service environment. Based on the polarization characteristic curves and layered soil resistivity detected in a real service environment, this application can effectively improve the accuracy of numerical simulation calculations, thereby obtaining more accurate results of the impact of high-voltage DC interference on the pipeline. The impact results can effectively reflect the impact of pipeline corrosion under high-voltage DC interference, provide an important reference for pipeline risk assessment, and improve the reliability of safe pipeline operation.

In some embodiments of the present application, the process of step S2, measuring the resistivity of layered soil in the area affected by high voltage DC interference on the pipeline sample by using the Wenner quadrupole method, is introduced, which may specifically include:

Step S21, setting four test sites within a preset distance of the pipeline sample, and using the Wenner quadrupole method to test the soil resistivity at a preset number of different depth positions.

Specifically, four test sites are set within a preset distance of the pipeline sample on site. All test sites should be within the influence area of high-voltage DC interference on the pipeline sample. The Wenner quadrupole method is used to test the soil resistivity at several preset different depth positions.

Step S22: Calculate the average value of the soil resistivity at the plurality of different depths and use it as the layered soil resistivity of the area affecting the pipeline sample.

Specifically, the soil resistivities at several different depths obtained by measurement are averaged, and the average value obtained is used as the layered soil resistivity of the area affecting the pipeline sample.

The following is a description of a high-voltage DC interference testing device provided in an embodiment of the present application. The high-voltage DC interference testing device described below and the high-voltage DC interference testing method described above can refer to each other.

Refer to FIG3 , which is a schematic diagram of the structure of a high-voltage DC interference testing device disclosed in an embodiment of the present application.

As shown in FIG3 , the high voltage DC interference test device may include:

The polarization characteristic determination unit 110 is used to monitor the natural corrosion potential of the pipeline sample in real time, and after the natural corrosion potential is stabilized, test the polarization characteristic curve of the pipeline sample through a pre-set polarization characteristic test device;

The layer resistivity determination unit 120 is used to measure the layer soil resistivity of the area affected by the high voltage DC interference on the pipeline sample by using the Wenner quadrupole method;

The interference model establishment unit 130 is used to establish a geometric model of the pipeline subjected to high voltage direct current interference based on the polarization characteristic curve of the pipeline sample and the resistivity of the layered soil by using a boundary element numerical simulation method;

A boundary curve determination unit 140, configured to calculate a polarization boundary curve of the pipeline sample based on the polarization characteristic curve of the pipeline sample and a damage rate of an outer anti-corrosion coating of the metal material to be tested that makes up the pipeline sample;

The impact result determination unit is used to determine the impact result of the high-voltage direct current interference on the pipeline based on the geometric model of the pipeline being interfered by the high-voltage direct current and the polarization boundary conditions of the pipeline sample.

It can be seen from the above technical solutions that the high-voltage DC interference test device provided in the embodiment of the present application monitors the natural corrosion potential of the pipeline sample in real time. After the natural corrosion potential is stabilized, the polarization characteristic curve of the pipeline sample is tested by a pre-set polarization characteristic test device, and then the layered soil resistivity of the area affected by the high-voltage DC interference on the pipeline sample is measured by the Wenner quadrupole method to establish a geometric model of the pipeline affected by the high-voltage DC interference. Based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample, the polarization boundary curve of the pipeline sample is calculated, and finally, based on the geometric model of the pipeline affected by the high-voltage DC interference and the polarization boundary conditions of the pipeline sample, the impact result of the high-voltage DC interference on the pipeline is determined.

This application utilizes a polarization characteristic test device consisting of a working electrode, an auxiliary electrode, a reference electrode, a support tube, and an electrochemical workstation to accurately measure the polarization characteristics of the pipeline in a real service environment. At the same time, the Wenner quadrupole method is used to measure the layered soil resistivity of the area affected by high-voltage DC interference in a real service environment. Based on the polarization characteristic curves and layered soil resistivity detected in a real service environment, this application can effectively improve the accuracy of numerical simulation calculations, thereby obtaining more accurate results of the impact of high-voltage DC interference on the pipeline. The impact results can effectively reflect the impact of pipeline corrosion under high-voltage DC interference, provide an important reference for pipeline risk assessment, and improve the reliability of safe pipeline operation.

Optionally, the layered resistivity determination unit may include:

A resistivity determination unit is used to set four test sites within a preset distance of the pipeline sample and test the soil resistivity at a preset number of different depths using a Wenner quadrupole method;

The average calculation unit is used to calculate the average value of the soil resistivity at the plurality of different depth positions and use it as the layered soil resistivity of the area affecting the pipeline sample.

Optionally, the process of the polarization characteristic determination unit testing the polarization characteristic curve of the pipeline sample by the polarization characteristic testing device may include:

The polarization characteristic test device gradually moves negatively from the natural corrosion potential to -1500mV _CSE in steps of 0.5-1mV/s, measures the relationship between the polarization potential and the polarization current density of the pipeline sample, and generates a polarization characteristic curve of the pipeline sample.

Optionally, the process of calculating the polarization boundary curve of the pipeline sample by the boundary curve determination unit based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample may include:

The polarization potential is kept unchanged, the product of the external anti-corrosion coating breakage rate of the metal material to be tested and the polarization current density of the pipeline sample is used as the new polarization current density, the polarization characteristic curve of the pipeline sample is adjusted, and the polarization boundary curve of the pipeline sample is generated.

Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

The above description of the disclosed embodiments enables professionals and technicians in the field to implement or use the present application. Various modifications to these embodiments will be apparent to professionals and technicians in the field, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. The various embodiments can be combined with each other. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims (2)

1. A method for testing high voltage DC interference, comprising: Real-time monitoring of the natural corrosion potential of the pipeline sample, and after the natural corrosion potential is stabilized, testing the polarization characteristic curve of the pipeline sample by a pre-set polarization characteristic testing device; The Wenner quadrupole method was used to measure the resistivity of the layered soil in the area affected by high voltage DC interference on the pipeline specimen. Using boundary element numerical simulation method, based on the polarization characteristic curve of the pipeline sample and the resistivity of the layered soil, a geometric model of the pipeline subjected to high voltage direct current interference is established; Determine the damage rate of the outer anti-corrosion coating of the metal material to be tested according to the type of the anti-corrosion layer of the metal material to be tested that makes the pipeline sample, and calculate the polarization boundary curve of the pipeline sample based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested that makes the pipeline sample; Based on the geometric model of the pipeline being interfered by high voltage direct current and the polarization boundary conditions of the pipeline sample, determining the influence result of the high voltage direct current interference on the pipeline; The Wenner quadrupole method is used to measure the resistivity of layered soil in the area affected by high voltage DC interference on the pipeline, including: Four test sites are set within a preset distance of the pipeline sample, and the soil resistivity at a preset number of different depths is tested using the Wenner quadrupole method; Calculating an average value of the soil resistivity at the plurality of different depths and using the average value as the layered soil resistivity of the area affected by the pipeline sample; Testing the polarization characteristic curve of the pipeline sample by the polarization characteristic testing device includes: The polarization characteristic test device gradually moves negatively from the natural corrosion potential to -1500mV _CSE in steps of 0.5-1mV/s, measures the relationship between the polarization potential and the polarization current density of the pipeline sample, and generates a polarization characteristic curve of the pipeline sample; Based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample, the polarization boundary curve of the pipeline sample is calculated, including: The polarization characteristic curve of the pipeline sample is corrected by using the damage rate of the outer anti-corrosion coating of the metal material to be tested which is used to make the pipeline sample; The polarization potential is kept unchanged, the product of the external anti-corrosion coating breakage rate of the metal material to be tested and the polarization current density of the pipeline sample is used as the new polarization current density, the polarization characteristic curve of the pipeline sample is adjusted, and the polarization boundary curve of the pipeline sample is generated. 2. A high voltage DC interference test device, comprising: A polarization characteristic determination unit, used for real-time monitoring of the natural corrosion potential of the pipeline sample, and after the natural corrosion potential is stabilized, testing the polarization characteristic curve of the pipeline sample by a pre-set polarization characteristic testing device; A layer resistivity determination unit for measuring the layer soil resistivity in the area affected by high voltage DC interference on the pipeline specimen using the Wenner quadrupole method; An interference model establishment unit is used to establish a geometric model of the pipeline being interfered by high voltage direct current based on the polarization characteristic curve of the pipeline sample and the resistivity of the layered soil by using a boundary element numerical simulation method; a boundary curve determining unit, for determining the damage rate of the outer anti-corrosion coating of the metal material to be tested according to the type of the anti-corrosion layer of the metal material to be tested made of the pipeline sample, and calculating the polarization boundary curve of the pipeline sample based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample; An impact result determination unit, used to determine the impact result of the high-voltage DC interference on the pipeline based on the geometric model of the pipeline being interfered with by the high-voltage DC and the polarization boundary conditions of the pipeline sample; The layer resistivity determination unit comprises: A resistivity determination unit is used to set four test sites within a preset distance of the pipeline sample and test the soil resistivity at a preset number of different depths using a Wenner quadrupole method; An average calculation unit, used for calculating the average value of the soil resistivity at the plurality of different depth positions and taking the average value as the layered soil resistivity of the area affected by the pipeline sample; Testing the polarization characteristic curve of the pipeline sample by the polarization characteristic testing device includes: The polarization characteristic test device gradually moves negatively from the natural corrosion potential to -1500mV _CSE in steps of 0.5-1mV/s, measures the relationship between the polarization potential and the polarization current density of the pipeline sample, and generates a polarization characteristic curve of the pipeline sample; Based on the polarization characteristic curve of the pipeline sample and the damage rate of the outer anti-corrosion coating of the metal material to be tested made of the pipeline sample, the polarization boundary curve of the pipeline sample is calculated, including: The polarization characteristic curve of the pipeline sample is corrected by using the damage rate of the outer anti-corrosion coating of the metal material to be tested which is used to make the pipeline sample; The polarization potential is kept unchanged, the product of the external anti-corrosion coating damage rate of the metal material to be tested and the polarization current density of the pipeline sample is used as the new polarization current density, the polarization characteristic curve of the pipeline sample is adjusted, and the polarization boundary curve of the pipeline sample is generated.